1. Field of the Invention
The present invention relates to a method of OPC model building, an information-processing apparatus, and a method of determining the process conditions of a semiconductor device. More particularly, the present invention relates to, for example, OPC modeling used in lithography requiring dissecting a pattern loyal to design data in ultra-microfabrication and in the field of semiconductor processes, and to the utilization of the OPC modeling.
2. Background Art
In the field of semiconductor processes, optical proximity correction (hereinafter referred as OPC) is carried out in some cases, in order to approximate a pattern on a wafer to a desired object (for example, CAD design). OPC is a technique especially effective in forming a microscopic pattern on a wafer.
Methods of OPC include making a length measurement and a comparison of post-transfer pattern sizes using OPC-processed and non-OPC-processed mask patterns to create a database of these pattern sizes and thereby perform mathematical modeling (hereinafter referred to as modeling or OPC modeling). In addition, main types of length-measurement data necessary for modeling include line length-measurement data, space length-measurement data, and hole length-measurement data. A pattern transferred onto a wafer varies in a variety of ways, depending on a difference in the type and size of the pattern and on the combination of a distance between adjacent patterns, a pattern density, and the like. By quantifying and making a database of these variations using length-measurement values, it is possible to define rules for OPC processing. The shape and size of a pattern needed for the process in question are determined on the basis of the created database and these data items serve as one of parameters in device design.
For example, JP Patent Publication (Kokai) No. 2006-126532A (corresponding to US2006/0108524) discloses a method of mask pattern synthesis in which optical proximity correction is performed on a mask pattern identified by design pattern data by applying an OPC pattern from a reference database. This reference database stores data as to what OPC pattern should be disposed on a given design pattern to enable an actual mask pattern to approximate to that design pattern.